Crown gall, Michigan trees, shrubs

Integrated pest management resources for Michigan

IPM Scouting in Woody Landscape Plants

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Crown gall

Cause: Agrobacterium tumefaciens (bacterium)

Hosts: Creeping euonymus, rose, willow, and poplar are particularly susceptible. This bacterium produces tumor-like growths on plant crowns, branches, and roots.

Management: Remove and destroy severely affected plants. Galled parts can be pruned off; disinfest tools frequently when pruning. Avoid replanting susceptible plants in areas where infected plants have been removed. The bacterium enters through wounds and can persist in the soil for many years after infected plants are removed. A commercially-available biological control agent, Agrobacterium radiobacter, can be used as a dip or spray to treat bare root plants, such as roses, before planting.

Galls, shown here on euonymus, can range in size from about pea-sized to golf-ball size or larger. Galls start out spongy, and cream or green colored and become dark and woody with age.

Additional information

MSU Diagnostic Services for assistance in pest identification.
MSU Landscape Alert newsletters for information about the current growing season, pest concerns and plant advice.

This information was developed from A Pocket IPM Scouting Guide for Woody Landscape Plants by Diane Brown-Rytlewski. Purchase this in a pocket-sized guide for reference in the orchard from MSU Extension (publication E-2839).

The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the Michigan Agricultural Experiment Station, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.
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Updated 7/11/07